MDEV-10411 Providing compatibility for basic PL/SQL constructs

Part 5: EXIT statement

Adding unconditional EXIT statement:

  EXIT [ label ]

Conditional EXIT statements with WHERE clause
will be added in a separate patch.

mysql-test/suite/compat/oracle/r/sp-code.result

@@ -396,3 +396,113 @@ SELECT @v;
 @v
 324
 DROP PROCEDURE p1;
+#
+# Testing EXIT statement
+#
+CREATE FUNCTION f1 RETURN INT
+IS
+i INT := 0;
+BEGIN
+LOOP
+i:= i + 1;
+IF i >= 5 THEN
+EXIT;
+END IF;
+END LOOP;
+RETURN i;
+END;
+/
+SHOW FUNCTION CODE f1;
+Pos	Instruction
+0	set i@0 0
+1	set i@0 (i@0 + 1)
+2	jump_if_not 1(1) (i@0 >= 5)
+3	jump 4
+4	freturn 3 i@0
+SELECT f1() FROM DUAL;
+f1()
+5
+DROP FUNCTION f1;
+CREATE FUNCTION f1 RETURN INT
+IS
+i INT := 0;
+BEGIN
+LOOP
+BEGIN
+i:= i + 1;
+IF i >= 5 THEN
+EXIT;
+END IF;
+EXCEPTION
+WHEN OTHERS THEN i:= 1000;
+END;
+END LOOP;
+RETURN i;
+END;
+/
+SHOW FUNCTION CODE f1;
+Pos	Instruction
+0	set i@0 0
+1	jump 5
+2	set i@0 (i@0 + 1)
+3	jump_if_not 8(8) (i@0 >= 5)
+4	jump 10
+5	hpush_jump 2 1 EXIT
+6	set i@0 1000
+7	hreturn 0 8
+8	hpop 1
+9	jump 5
+10	freturn 3 i@0
+SELECT f1() FROM DUAL;
+f1()
+5
+DROP FUNCTION f1;
+CREATE PROCEDURE p1(a IN OUT INT)
+IS
+i INT := 0;
+BEGIN
+LOOP
+LOOP
+BEGIN
+i:= i + 1;
+IF i >=5 THEN
+EXIT;
+END IF;
+EXCEPTION
+WHEN OTHERS THEN a:=1000;
+END;
+END LOOP;
+i:= i + 100;
+EXIT;
+END LOOP;
+a:= i;
+EXCEPTION
+WHEN OTHERS THEN a:=11;
+END;
+/
+SHOW PROCEDURE CODE p1;
+Pos	Instruction
+0	set i@1 0
+1	jump 14
+2	set i@1 (i@1 + 1)
+3	jump_if_not 8(8) (i@1 >= 5)
+4	jump 10
+5	hpush_jump 2 2 EXIT
+6	set a@0 1000
+7	hreturn 0 8
+8	hpop 1
+9	jump 5
+10	set i@1 (i@1 + 100)
+11	jump 12
+12	set a@0 i@1
+13	jump 17
+14	hpush_jump 5 2 EXIT
+15	set a@0 11
+16	hreturn 0 17
+17	hpop 1
+set @v= 10;
+CALL p1(@v);
+SELECT @v;
+@v
+105
+DROP PROCEDURE p1;

mysql-test/suite/compat/oracle/r/sp.result

@@ -493,3 +493,95 @@ SELECT @v;
 @v
 10
 DROP PROCEDURE sp1;
+#
+# Testing EXIT statement
+#
+CREATE FUNCTION f1 RETURN INT
+IS
+i INT := 0;
+BEGIN
+EXIT;
+END;
+/
+ERROR 42000: EXIT with no matching label: 
+CREATE FUNCTION f1 RETURN INT
+IS
+i INT := 0;
+BEGIN
+<<lable1>>
+BEGIN
+<<label2>>
+LOOP
+EXIT label1;
+END LOOP;
+END;
+END;
+/
+ERROR 42000: EXIT with no matching label: label1
+CREATE FUNCTION f1 RETURN INT
+IS
+i INT := 0;
+BEGIN
+LOOP
+LOOP
+i:= i + 1;
+IF i >= 5 THEN
+EXIT;
+END IF;
+END LOOP;
+i:= i + 100;
+EXIT;
+END LOOP;
+RETURN i;
+END;
+/
+SELECT f1() FROM DUAL;
+f1()
+105
+DROP FUNCTION f1;
+CREATE FUNCTION f1 RETURN INT
+IS
+i INT := 0;
+BEGIN
+<<label1>>
+LOOP
+<<label2>>
+LOOP
+i:= i + 1;
+IF i >= 5 THEN
+EXIT label2;
+END IF;
+END LOOP;
+i:= i + 100;
+EXIT;
+END LOOP;
+RETURN i;
+END;
+/
+SELECT f1() FROM DUAL;
+f1()
+105
+DROP FUNCTION f1;
+CREATE FUNCTION f1 RETURN INT
+IS
+i INT := 0;
+BEGIN
+<<label1>>
+LOOP
+<<label2>>
+LOOP
+i:= i + 1;
+IF i >= 5 THEN
+EXIT label1;
+END IF;
+END LOOP;
+i:= i + 100;
+EXIT;
+END LOOP;
+RETURN i;
+END;
+/
+SELECT f1() FROM DUAL;
+f1()
+5
+DROP FUNCTION f1;

mysql-test/suite/compat/oracle/t/sp-code.test

@@ -319,3 +319,81 @@ SET @v=10;
 CALL p1(@v);
 SELECT @v;
 DROP PROCEDURE p1;
+
+--echo #
+--echo # Testing EXIT statement
+--echo #
+
+DELIMITER /;
+CREATE FUNCTION f1 RETURN INT
+IS
+  i INT := 0;
+BEGIN
+  LOOP
+    i:= i + 1;
+    IF i >= 5 THEN
+      EXIT;
+    END IF;
+  END LOOP;
+  RETURN i;
+END;
+/
+DELIMITER ;/
+SHOW FUNCTION CODE f1;
+SELECT f1() FROM DUAL;
+DROP FUNCTION f1;
+
+DELIMITER /;
+CREATE FUNCTION f1 RETURN INT
+IS
+  i INT := 0;
+BEGIN
+  LOOP
+    BEGIN
+      i:= i + 1;
+      IF i >= 5 THEN
+        EXIT;
+      END IF;
+    EXCEPTION
+      WHEN OTHERS THEN i:= 1000;
+    END;
+  END LOOP;
+  RETURN i;
+END;
+/
+DELIMITER ;/
+SHOW FUNCTION CODE f1;
+SELECT f1() FROM DUAL;
+DROP FUNCTION f1;
+
+
+DELIMITER /;
+CREATE PROCEDURE p1(a IN OUT INT)
+IS
+  i INT := 0;
+BEGIN
+  LOOP
+    LOOP
+      BEGIN
+        i:= i + 1;
+        IF i >=5 THEN
+          EXIT;
+        END IF;
+      EXCEPTION
+        WHEN OTHERS THEN a:=1000;
+      END;
+    END LOOP;
+    i:= i + 100;
+    EXIT;
+  END LOOP;
+  a:= i;
+EXCEPTION
+  WHEN OTHERS THEN a:=11;
+END;
+/
+DELIMITER ;/
+SHOW PROCEDURE CODE p1;
+set @v= 10;
+CALL p1(@v);
+SELECT @v;
+DROP PROCEDURE p1;

mysql-test/suite/compat/oracle/t/sp.test

@@ -525,3 +525,110 @@ SET @v=10;
 CALL sp1(@v, 30002);
 SELECT @v;
 DROP PROCEDURE sp1;
+
+
+--echo #
+--echo # Testing EXIT statement
+--echo #
+
+DELIMITER /;
+--error ER_SP_LILABEL_MISMATCH
+CREATE FUNCTION f1 RETURN INT
+IS
+  i INT := 0;
+BEGIN
+  EXIT;
+END;
+/
+DELIMITER ;/
+
+
+DELIMITER /;
+--error ER_SP_LILABEL_MISMATCH
+CREATE FUNCTION f1 RETURN INT
+IS
+  i INT := 0;
+BEGIN
+  <<lable1>>
+  BEGIN
+    <<label2>>
+    LOOP
+      EXIT label1;
+    END LOOP;
+  END;
+END;
+/
+DELIMITER ;/
+
+
+DELIMITER /;
+CREATE FUNCTION f1 RETURN INT
+IS
+  i INT := 0;
+BEGIN
+  LOOP
+    LOOP
+      i:= i + 1;
+      IF i >= 5 THEN
+        EXIT;
+      END IF;
+    END LOOP;
+    i:= i + 100;
+    EXIT;
+  END LOOP;
+  RETURN i;
+END;
+/
+DELIMITER ;/
+SELECT f1() FROM DUAL;
+DROP FUNCTION f1;
+
+
+DELIMITER /;
+CREATE FUNCTION f1 RETURN INT
+IS
+  i INT := 0;
+BEGIN
+  <<label1>>
+  LOOP
+    <<label2>>
+    LOOP
+      i:= i + 1;
+      IF i >= 5 THEN
+        EXIT label2;
+      END IF;
+    END LOOP;
+    i:= i + 100;
+    EXIT;
+  END LOOP;
+  RETURN i;
+END;
+/
+DELIMITER ;/
+SELECT f1() FROM DUAL;
+DROP FUNCTION f1;
+
+
+DELIMITER /;
+CREATE FUNCTION f1 RETURN INT
+IS
+  i INT := 0;
+BEGIN
+  <<label1>>
+  LOOP
+    <<label2>>
+    LOOP
+      i:= i + 1;
+      IF i >= 5 THEN
+        EXIT label1;
+      END IF;
+    END LOOP;
+    i:= i + 100;
+    EXIT;
+  END LOOP;
+  RETURN i;
+END;
+/
+DELIMITER ;/
+SELECT f1() FROM DUAL;
+DROP FUNCTION f1;

sql/sp_pcontext.cc

@@ -197,10 +197,11 @@ sp_variable *sp_pcontext::add_variable(THD *thd, LEX_STRING name)
 }
 
 
-sp_label *sp_pcontext::push_label(THD *thd, LEX_STRING name, uint ip)
+sp_label *sp_pcontext::push_label(THD *thd, LEX_STRING name, uint ip,
+                                  sp_label::enum_type type)
 {
   sp_label *label=
-    new (thd->mem_root) sp_label(name, ip, sp_label::IMPLICIT, this);
+    new (thd->mem_root) sp_label(name, ip, type, this);
 
   if (!label)
     return NULL;
@@ -236,6 +237,23 @@ sp_label *sp_pcontext::find_label(const LEX_STRING name)
 }
 
 
+sp_label *sp_pcontext::find_label_current_loop_start()
+{
+  List_iterator_fast<sp_label> li(m_labels);
+  sp_label *lab;
+
+  while ((lab= li++))
+  {
+    if (lab->type == sp_label::ITERATION)
+      return lab;
+  }
+  // See a comment in sp_pcontext::find_label()
+  return (m_parent && (m_scope == REGULAR_SCOPE)) ?
+         m_parent->find_label_current_loop_start() :
+         NULL;
+}
+
+
 bool sp_pcontext::add_condition(THD *thd,
                                 LEX_STRING name,
                                 sp_condition_value *value)

sql/sp_pcontext.h

@@ -402,10 +402,18 @@ public:
   // Labels.
   /////////////////////////////////////////////////////////////////////////
 
-  sp_label *push_label(THD *thd, const LEX_STRING name, uint ip);
+  sp_label *push_label(THD *thd, const LEX_STRING name, uint ip,
+                       sp_label::enum_type type);
+
+  sp_label *push_label(THD *thd, const LEX_STRING name, uint ip)
+  {
+    return push_label(thd, name, ip, sp_label::IMPLICIT);
+  }
 
   sp_label *find_label(const LEX_STRING name);
 
+  sp_label *find_label_current_loop_start();
+
   sp_label *last_label()
   {
     sp_label *label= m_labels.head();

sql/sql_lex.cc

@@ -5312,8 +5312,7 @@ bool LEX::sp_handler_declaration_finalize(THD *thd, int type)
 
 void LEX::sp_block_init(THD *thd, const LEX_STRING label)
 {
-  sp_label *lab= spcont->push_label(thd, label, sphead->instructions());
+  spcont->push_label(thd, label, sphead->instructions(), sp_label::BEGIN);
-  lab->type= sp_label::BEGIN;
   spcont= spcont->push_context(thd, sp_pcontext::REGULAR_SCOPE);
 }
 
@@ -5478,7 +5477,12 @@ bool LEX::sp_leave_statement(THD *thd, const LEX_STRING label_name)
     my_error(ER_SP_LILABEL_MISMATCH, MYF(0), "LEAVE", label_name.str);
     return true;
   }
+  return sp_exit_block(thd, lab);
+}
 
+
+bool LEX::sp_exit_block(THD *thd, sp_label *lab)
+{
   /*
     When jumping to a BEGIN-END block end, the target jump
     points to the block hpop/cpop cleanup instructions,
@@ -5493,6 +5497,31 @@ bool LEX::sp_leave_statement(THD *thd, const LEX_STRING label_name)
 }
 
 
+bool LEX::sp_exit_statement(THD *thd)
+{
+  sp_label *lab= spcont->find_label_current_loop_start();
+  if (!lab)
+  {
+    my_error(ER_SP_LILABEL_MISMATCH, MYF(0), "EXIT", "");
+    return true;
+  }
+  DBUG_ASSERT(lab->type == sp_label::ITERATION);
+  return sp_exit_block(thd, lab);
+}
+
+
+bool LEX::sp_exit_statement(THD *thd, const LEX_STRING label_name)
+{
+  sp_label *lab= spcont->find_label(label_name);
+  if (!lab || lab->type != sp_label::ITERATION)
+  {
+    my_error(ER_SP_LILABEL_MISMATCH, MYF(0), "EXIT", label_name);
+    return true;
+  }
+  return sp_exit_block(thd, lab);
+}
+
+
 bool LEX::sp_iterate_statement(THD *thd, const LEX_STRING label_name)
 {
   sp_label *lab= spcont->find_label(label_name);
@@ -5527,8 +5556,8 @@ bool LEX::sp_push_loop_label(THD *thd, const LEX_STRING label_name)
     my_error(ER_SP_LABEL_REDEFINE, MYF(0), label_name.str);
     return true;
   }
-  lab= spcont->push_label(thd, label_name, sphead->instructions());
+  spcont->push_label(thd, label_name, sphead->instructions(),
-  lab->type= sp_label::ITERATION;
+                     sp_label::ITERATION);
   return false;
 }
 
@@ -5538,7 +5567,8 @@ bool LEX::sp_push_loop_empty_label(THD *thd)
   if (maybe_start_compound_statement(thd))
     return true;
   /* Unlabeled controls get an empty label. */
-  spcont->push_label(thd, empty_lex_str, sphead->instructions());
+  spcont->push_label(thd, empty_lex_str, sphead->instructions(),
+                     sp_label::ITERATION);
   return false;
 }
 

sql/sql_lex.h

@@ -3152,6 +3152,9 @@ public:
                                                   uint executable_section_ip,
                                                   uint exception_count);
   bool sp_change_context(THD *thd, const sp_pcontext *ctx, bool exclusive);
+  bool sp_exit_block(THD *thd, sp_label *lab);
+  bool sp_exit_statement(THD *thd);
+  bool sp_exit_statement(THD *thd, const LEX_STRING label_name);
   bool sp_leave_statement(THD *thd, const LEX_STRING label_name);
   bool sp_iterate_statement(THD *thd, const LEX_STRING label_name);
 

sql/sql_yacc_ora.yy

@@ -1260,6 +1260,7 @@ END_OF_INPUT
 %type <NONE> sp_proc_stmt_if
 %type <NONE> sp_labeled_control sp_unlabeled_control
 %type <NONE> sp_labeled_block sp_unlabeled_block sp_unlabeled_block_not_atomic
+%type <NONE> sp_proc_stmt_exit
 %type <NONE> sp_proc_stmt_leave
 %type <NONE> sp_proc_stmt_iterate
 %type <NONE> sp_proc_stmt_open sp_proc_stmt_fetch sp_proc_stmt_close
@@ -2858,6 +2859,7 @@ sp_proc_stmt_in_returns_clause:
 sp_proc_stmt:
           sp_proc_stmt_in_returns_clause
         | sp_proc_stmt_statement
+        | sp_proc_stmt_exit
         | sp_proc_stmt_leave
         | sp_proc_stmt_iterate
         | sp_proc_stmt_open
@@ -2961,6 +2963,19 @@ sp_proc_stmt_return:
           }
         ;
 
+sp_proc_stmt_exit:
+          EXIT_SYM
+          {
+            if (Lex->sp_exit_statement(thd))
+              MYSQL_YYABORT;
+          }
+        | EXIT_SYM label_ident
+          {
+            if (Lex->sp_exit_statement(thd, $2))
+              MYSQL_YYABORT;
+          }
+        ;
+
 sp_proc_stmt_leave:
           LEAVE_SYM label_ident
           {